I have a range of ideas for a possible DLC.
WARNING: These maps do not have much story inspiration.
Complex: This map is set in an abandoned storage complex in a secret location. There are three teams: MI6, CIA and the KGB. It is a large map with many new features like trams, ziplines and a new free-running system. Also, vehicles such as bikes, cars and even fork-lifts will be usable. There will be shafts that you can crawl through, and interactive shaft doors, so you can drop out of the bottom of a shaft and surprise your enemies. Also, there is RC-XD tunnels that run under the map.
Snowdrift: This map is set in a city in Iceland. This map will also feature three teams: Arctic MI6, Arctic KGB and a new team, Camouflage Black Ops. Like the last map, there will be vehicles. The same vehicles appear, but a new vehicle is added: the digger. As with Complex, there will be a free-running system. Crawling shafts also make an appearance, but there are no RC-XD tunnels. New weapons are in Snowdrift: the MP7A1, PP9, MP5 (and MP5SD), and the Five-Seven pistol.
And now for the most important feature in the DLC... the zombie map! The map featured is named Der Letzte Tag, which translates to 'The Final Day'. Dempsey returns, as does Richtofen and Nikolai, but Takeo has been replaced by a mysterious British man.